Mechanism for truing and dressing grinding wheels



E. R.-CONNERS' MECHANISM FOR TRUING AND DRESSING GRINDING WHEEL Filed Oct. 27. 1921 June 10- 1924.

Patented June 10, 1924.

EDWARD R. CONNERS, OF CINOZNNATI, OHIO, ASSIG-NOR TO THE PRECISION TRUING MACHINE AND TOOL COMPANY, OF CINCINNATI, OHICL'A CORPORATION OF OHIO.

MECHANISM FOR 'IR'UING AND DRESSING GRINDING WHEELS.

Application filed. October 27, 1921. Serial No. 510,728.

To aZZ whom it may concern:

Be it known that I, EDWARD R. Contains, a citizen of the United States, residing at Cincinnati, in the countyof Hamilton and State of Ohio, have invented certain new and useful Improvements in Mechanism for Truing and Dressing Grinding Wheels, of which the following is aspecification.

My invention relates to mechanism for truing and dressing grinding wheels, such as emery wheels employed in machinery for grinding or polishing the surfaces of metal in precision grinding. A usual means heretofore employed in truing and dressing grinding wheels of this character has been a diamond tool comprising a diamond made to contact the grinding surface of the grinding wheel. Diamonds have, however, become very scarce and very expensive. They also have the objection of providing only a substantially single point of contact with the grinding wheel, resulting in uneven dressing or polishing, or objectionable scoring of the grinding surface of the grinding wheel operated on.

It is the object of my invention to provide means to dispense with the use of diamonds for this purpose and to provide novel abrading means arrangedto present greater area of contact to thegrinding. wheel.

It is the object of my invention further to provide a rotary abrading part arranged to contact the grinding surface of a grinding wheel in such manner as to cause rotation to be imparted to the rotary abrading part by the rotating grinding wheel and means closely associated with the rotary abrading part whereby such rotation is maintained during intervals between contacts between the rotary abrading part and the grinding wheel.

It is the object of my invention further to provide a rotary abrading part arranged to contact the grinding surface of a grinding wheel in such manner as to cause rotation to be imparted to the rotary abrading part by the rotating grinding wheel and means closely associated with the rotary abrading part whereby such rotation is maintained during intervals between contacts between the rotary abrading part and the grinding wheel.

Iv have exemplified my present, invention as a hand tool arranged for manually presenting the rotary abrading part to the grinding wheel to be trued or dressed.

My present invention is an elaboration of the inventions shown, described and claimed in my copending. applications for Letters Patent of the'Uniteol States for devices for truing. and dressing grinding wheels, respectively Serial No. 199,889," filed November 2, 1917, and Serial No. 366,970, filed March 18, 1920, and for mechanisms for truing and dressing grinding wheels, Serial No. 415,402, filed October 7, 1920, Serial No.

415,403, filed October 7, 1920, and issued to a grinding wheel, the latter partly broken Fig. 2 is an axial section of my improved device, taken on the line 22 of Fig. 1; and,

Fig. 3 is a plan View of my improved device, partly in section on the line 3-3 of Fig. 1, and shownin connection with a grinding wheel, the latter partly broken away.

My improved device is employable while the grinding wheel is performing its grinding operations, as more fully shown, described and claimed in connection with the rotary abrading parts in my aforesaid applications, and is also applicable for truing or dressing a rotating grinding wheel by hand while the grinding wheel is not performing its grinding function or when disconnected from the machine in which it performs its grinding operations,

The grinding wheel is exemplified at 11 and is arranged to be rotated in any suitable manner, such rotation being imparted to it for instance in the direction of the arrow a during the application thereto of my improved d vice.

Grinding wheels of this character in course of time become impregnated with particles of dirt and metal from the work being operated on and become comparatively glossy and thereby lose their grinding effect. The grinding wheel may also in course of operation become out of true, that is to say, its grinding pe 'iphery or grinding surface will no longer be a true cylinder, if a cylindrical grinding surface be employed or its granular structure may be come dull.

By means of my invention the particles of dirt and metal are removed from the grinding wheel, and the recesses and pores in the grinding surface of the rotary grinding wheel are cleared and the particles or grains of the grinding wheel are sharpened.

The rotary abrading part, shown at 12, is exemplified a nib or pencil. hereinafter called a pencil. and is preferably of a car- 'borundum material and of a texture much harder than the texture of the grinding wheel to be trued or dressed. The rotary abrading pencil is exemplified as having an axial bore 13, the outer or abrading end of" which is surrounded by a trusto-conical abrading face 14:.

The abrading pencil employed may be such as is more fully shown. and described and claimed in my copending application for Letters Patent of the United States for abrading pencils. Serial No, 498,732. filed September 6, 1921. The abrading pencil is exemplified as having a body, the radii of which are of greater lengths than the diameter of its bore and the length of its body is exemplified as lengths of said radii.

I provide means for supporting the pen cil. and also for maintaini its rotation tor a considerable period of tune after contact between the rotary abrading pencil and the rotating grinding wheel is released. so that. upon contact being again made. the rotary abrading pencil will again. instantly attack the grinding surface with abrading: effect. I associate the means for accomplishing the latter result closely with the abrading pencil, so as to prevent lost motion and to impart the inertia of rotation of a rotating body closely and directly to the rotary abrading part.

Thus-I provide a rotor 21, whiz-h cornprises a chuck 9,2 and a fly-wheel 23. the chuckand fly-wheel being shown associated and preferably integral with each other.

The chuck 22 is provided with a recess 24- for securing the rotary abrading pencil in place. One end of the rotary abrading penoil isreceived in this recess. a set-screw 25 clamping the rotary abrading pencil to the chuck. The chuck is exemplified as a solid chuck.

A shank 31 is exemplified as comprising greater than the stem 32, a sleeve 33 received about tne stem. and a handle received about the sleeve. The sleeve is provided with a reduced. hortion 35 about which ball-bearings 36, 37, are received. The inner end of the stem is provided with an annular flange 38. The re duced portion of the sleeve forms a shoulder 39. he inner ball-races 4:1, 42, ot' the ballbearings are respectively received against the fiange 38 and the shoulder 39.

The rotary abrading pencil is normally quiescent. The fly-wheel 23 is provided close to the chuck to maintain the rotation the rotary abrading pencil, after said rotation has been initiated by contact therewith by the rotating grinding wheel. which is exemplified as the sole means for rotating the rotary abrading pencil.

The fly-wheel is so proportioned with lation to the rotary abrading pencil that the inertia of rotation of the fly-wheel is greater than the inertia of rotation of the rotary abrading pencil. The fly-wheel is prefen ably heavier than the rotary abrading pencil, and is preferably composed of a suitable metal. In practice high speeds of rotation are imparted to the fly-wheel by contact of therotary abrading part with the grinding surface of the rotating grinding wheel.

Rotation of the rotary abrading pencil is by this arrangement maintained for considerable periods of time between contacts between the rotary abrading part and the grinding wheel so as to maintain momentum of rotation of the rotary abrading pencil with sufficient speed and force to act with a rotating abrading effect upon the grinding wheel as soon as contact is made therebe tween after intervals of release of said contact during the truing or dressing operation.

The fly-wheel is provided with a recess having an annular shouldertti. The ballbearings a e received in said recess, the outer hall-races 4-7, 48. being squeezed within the annular wall ct said recess for aiding in positioning the same. The outer ballrace 4.17 is received against said shoulder. The outer ball-races are preferably separated by a washer 49. A closing plate is received in an annular rabbet 51 in the rear end of the fly-wheel and is secured in place. as by means of screws 52. received through said plate and into the fly-wheel.

The opposite end of the stem is threaded. as at for receiving a nut 56,whirh bears against the opposite" end of the sleeve for adjusting the stem and the sleeve in opposite axial directions, and thereby adjusting the ease of operation of the ball-bearings and to take up any wear therein. There is space 57 between the'end of the sleeve and the fiange 38 on the stem 32 to permit such adjustment. A jam-nut 58 is provided to lock the parts in adjusted positions.

The ball-bearings are preferably combined end-thrust and radial ball-bearings, so arranged that end-thrust resistance is imparted to the rotary a'brading pencil to definitely retain the rotary abrading pencil in its correct path of travel.

The fly-wheel has a chuck intimately connected therewith and the fly-wheel is close ly adjai'ent to the chuck, so that the operative parts are closely related and occupy little space. The chuck and fly-wheel. are shown integral with each other, whereby compactness of parts and steadiness of rota tion of the rotary abrading pencil is insured.

in oil-hole 61 communicates with the ballbearings and is arranged to be closed, for instance by a screw-plug 62.

A shell 65 is received about the fly-wheel and is secured to the sleeve for instance by means of a set-screw 66 threaded in the hub 67 of the shell and having clamping engagement with the sleeve. The handle 34 is received about the sleeve. A nut 69 is threaded about the threaded end 70 of the sleeve for clamping the handle between the hub 67 and the nut. The handle is preferably of wood or other suitable material which is readily held by the hands of the person who is manipulating the device. The shell is received about the fly-wheel and forms a protection to prevent injury by contact with the fly-wheel.

My improved device forms a readily manipulable device for the purpose intended. It is preferably presented to the grinding surface being trued or dressed so that its aXis of rotation is at a slight angle to a radial line of the grinding wheel, or so that;

its axis of rotation is projected in the line of a chord to the circle of the grinding wheel. Rapid rotation is imparted to the rotating abrading pencil by contact with the rotating grinding wheel, preferably in the direction of the arrow 7).

Diiferent degrees of fineness of truing or dressing grinding wheels are obtained by the directions in which the axis of rotation of the truing or dressing device is presented to said grinding surface. A positioning of the rotary abrading pencil so that its axis of rotation is proximate to a line radial to the axis of rotation of the grinding wheel will result in a dressing of the grinding wheel. with a finer surface, whereas, if. the rotary abrading pencil is positioned with its axis of rotation describing a chord to the circle of the grinding wheel or at an angle to plane perpendicular to the axis of rotation of the grinding wheel, the grinding surface will be trued or dressed with a coarser surface, the degree of coarseness depending on the degree which the axis of rotation of the abrading pencil departs from a substantially radial position.

Having thus fully described my invengrinding wheels, the combination of a shank comprising a manually manipulated handle, a rotor comprising a chuck for a rotary abrading part and a fly-wheeh'said chuck and said fly-wheel being in juxtaposition at the same end of said handle, and a protective shell. protectingly received about said fly-wheel and supported from said handle.

3. In mechanism for truing and dressing grinding wheels, the combination of a shank, afiy-wheel at one end of said shank, a ball-bearing between said last-named end of said shank and said fly-wheel, and a chuck integral with said fly-wheel, said chuck arranged for securing a rotary abrading part, and a non-rotating shell protectingly received about said fly-wheel.

i. In mechanism for truing and dressing grinding wheels, the combination of a shank, a fly-wheel at one end of said shank, a chuck at the same end of said shank, whereby to secure a rotary abrading part, and a shell protectingly received about said fly-wheel.

5. In mechanism for truing and dressing grinding wheels, the combination of a shank, a rotor comprising a chuck and a flywheel, radial and end-thrust ball-bearings between one end of said shank and said rotor arranged for controlling thrusts of said rotor in opposite directions lengthwise of the axis of rotation of said rotor, said chuck arranged for securing a rotary abrading part, and a protective shell received about said fly-wheel.

6. In mechanism for truing and dressing grinding wheels, the combination of a shank comprising a plurality of telescoping parts, combined radial and end-thrust ball-bearings about said telescoping parts, said telescoping parts having contact faces thereon for said ball-bearings, means for adjusting said telescoping parts in opposite directions for adjusting said ball-bearings, a rotor comprising a chuck and a fly-wheel received about said ball-bearings and having connection therewith for rotation of said rotor upon said shank, said chuck arranged for securing a rotary abrading part thereto, and a protective shell supported by said shank and protectingly received about said fly-wheel.

7. In mechanism for truing and dressing grinding wheels, the combination of a shank comprising a stem, a sleeve about said stem,

and a handle about said sleeve, said stem and said sleeve provided with oppositely disposed shoulders, ball-bearings between said shoulders, means for causing adjustment between said stem and said sleeve lengthwise of their axes for adjusting said ball-bearings, and a rotor comprising a chuck and a fly-Wheel, said chuck arranged for securing a rotary abrading part, and said handle arranged for manual manipulation of said rotary abrading part.

8. In mechanism for truing and dressing grinding wheels, the combination of a shank comprising a stem, a sleeve about said stem, and a handle about said sleeve, said stem and said sleeve provided with oppositely disposed shoulders, ball-bearings between said shoulders, means for causing adjustinent between said stem and said sleeve lengthwise of their axes for adjusting said ball-bearings, a rotor comprising a chuck and a fly-wheel, said chuck arranged for securing a rotary abrading part, and said handle arranged for manual manipulation of said rotary abrading part, and a protective shell extending from said shank and protectingly received about said rotary abrading part.

in testimony whereof, I have hereunto signed my name in the presence of two subscribing witnesses.

EDWARD R. CONNERS, In presence of DELMA WERNSING, C. J. KRAUsn. 

